The invention is directed to a field of action light for medical, particularly dental practice, whereby the lamp member containing at least one lamp and one reflector is provided with means for eliminating the heat generated by the lamp.
In the known light of this type such as U.S. Pat. No. 4,254,454, which comprises a reflector that resides upright and is rectangular in plan view, a light-transmissive protective shield is arranged in front of the light, this protective shield forming a chamber together with the reflector and the housing of the light in whose center the lamp is located. The protective shield forms lateral openings in the region of the lamp via which cooling air can enter. Further gaps or, respectively, openings via which the heated air can emerge are formed together with the protective shield at the under edge and upper edge of the reflector as well as laterally therefrom.
An air circulation due to convection and, thus, elimination of the heat generated by the lamp is achieved with this design. What is thereby disadvantageous is that the warm air necessarily flows over the reflector and thereby unnecessarily heats it. As a consequence of the air circulation within the chamber, moreover, dust and other particles can constantly deposit on the protective shield and on the reflector, as a result whereof frequent cleaning of the reflector is necessary, this being possible in the said light only on the basis of a relatively complicated design. To this end, namely, the reflector is held at the housing of the light in a fashion so that it can be pivoted back. This pivotability requires relatively narrow manufacturing tolerances in order to achieve an exact adjustment of reflector and lamp.
The above disadvantages also apply to a multiple reflector system disclosed by U.S. Pat. No. 3,703,635 which is essentially provided for high-performance lamps, for example xenon high-pressure lamps in the power range between 2 and 8,000 Watts. The reflector system contains four reflectors, some of these being rigidly arranged and others being adjustably arranged in order to be able to vary the beam width from, for example, spot to flood. Axial ventilators are arranged at both ends of the reflector system for cooling. The front ventilator is arranged in a tube that extends in the direction of the reflector axis; the tube, however, only surrounds the lamp in a base region, i.e. only extends over a part of the lamp length. The tube contains radial slots both in the region of the front axial ventilator as well as in the region of the reflector, the air being capable of being suctioned in via these radial slots and being blown onto the reflector for cooling thereof.
U.S. Pat. No. 5,134,554 discloses an illumination system having a halogen lamp, whereby the lamp is surrounded by a pear shaped protective bell. The protective bell is provided with air outflow channels at its rear end with which it is secured to the base mount. The protective bell itself contains no air inflow opening.
British Patent 2 123 132 discloses a combined ventilator and illumination means that is preferably provided for fastening to the ceiling of a room. The means comprises a light fixture housing in which a ventilator and a fluorescent lamp are arranged. Two motors are arranged axially behind one another in the ventilator housing; one drives the ventilator wheel and a second turns a lamp shade at which the light as well as the cooling air emerge, as a result whereof the air outflow slots arranged in the lamp shade can be changed in position. The air exit direction can be varied with such an adjustment, and, thus, the air stream can be individually varied. In this elimination means, the light emanating from a fluorescent lamp emerges directly via slots; the illumination means thus contains no reflector. Further, no air inflow openings are present, either.